After she evaded Baoshan's attempts to stop her, Lan Yi found her way inside the cave easily. She'd nearly broken through the ancient power caging the Yin Iron when she heard the shout: “Lan Yi! Walk away! There’s still time to stop this!”

But Baoshan was too late. “I’m sorry, my friend,” Lan Yi said, and played the next note of the Song of Unbinding.

The earth under the cold spring cracked, then moved.

“No,” Baoshan whispered. She sounded like she might be crying; Lan Yi couldn’t spare even a moment’s attention to check.

“I waited for you, for so many years. I had thought you would be the last thing I ever saw in this life. Lan Yi, if you do this you won’t achieve immortality. You’ll be lucky to stay sane.”

But Gusu Lan must survive. Lan Yi knew the Yin Iron would ensure that. What kind of sect leader would she be if she didn’t try?

“I cannot achieve immortality through cowardice.”

Baoshan’s anger crested as the Yin Iron’s binding began to fail. Lan Yi pulled her hands from her guqin, watching the movement of the water. It would be twelve hours, maybe less. Already she could feel the Yin Iron’s power filling the cave, resentful energy magnifying Baoshan’s anger. For her part, with her superior control and Lan principles to fall back on, she merely felt distantly regretful. If only she could make Baoshan understand.

If only…

“Lan Yi,” Baoshan whispered. The scrape of metal in a sheath; Lan Yi whirled around in time to meet Baoshan blow for blow, forcing her back against the wall of the cave.

There was more than one way, Lan Yi knew, to conquer. Baoshan’s eyes were wide with terror: of Lan Yi? For her?

After all, why shouldn’t she? Leading Gusu Lan had taken so much from her. So many sleepless nights, pointless fights. Why shouldn’t she take something back? With the Yin Iron already whispering to her, she had so much power at her fingertips. Why not?

Why. Not.

“Lan Yi,” Baoshan whispered, and reached out to her with trembling hands. “Something’s wrong. I need you to stop it, Lan Yi. I can’t do it on my own. The Yin Iron wants you to hurt me. It wants…”

Poor, poor Baoshan. Even now she didn’t quite understand. “No, my love,” Lan Yi said. Baoshan’s eyes widened. Lan Yi smiled from the truth of it, the rightness burning through her veins.

“I want,” she said, and placed her hand on Baoshan’s neck, nails digging into her skin, pulling her in for a kiss.

For a moment Baoshan stood frozen, an immovable mountain Lan Yi could only press herself against. For a moment, cold and still as the cave around them, Lan Yi felt terror curling in her veins. Baoshan Sanren was her grandfather’s generation, a legend who’d outlived all her contemporaries. Who was Lan Yi to be touching her, kissing her, loving her?

The moment passed. Her terror curdled into anger as the seal weakened. Who is she to resist you? the Yin Iron whispered. Who is she to stop you from fucking her, taking her, keeping her?

“Lan Yi,” Baoshan said. Her voice was weaker now, softer, desire obvious as she said, “Can’t you feel it? It’s already corrupting you.”

“Baoshan, innocent Baoshan,” Lan Yi said. “How is it you’ve lived almost a hundred and fifty years and no one’s fucked you well enough to recognize the signs of wanting? It’s telling me to take what I want. It’s not telling me who that is.”

Baoshan’s eyes widened. The mountain moved.

Lan Yi found herself pressed against the shockingly cold cave wall, gasping into Baoshan’s mouth. Power coursed through her; why had she assumed Baoshan didn’t feel it as well? She held Lan Yi with unnatural strength, biting her shoulder, digging painful fingernails into her hips as she dragged Lan Yi’s innermost garments down to pool around her ankles. She kissed her again, a cruel grip at her hip, then lifted Lan Yi up past her chest, hooking Lan Yi’s legs over her shoulders and pushing her robes up until they were bunched at her waist.

“Stop squirming,” Baoshan said, the darkness in her voice not quite her own.

Lan Yi obeyed, and Baoshan leaned in, nuzzling at her thigh.

It was an awkward position to be in. The rock dug into her back and Lan Yi couldn’t help but think that if Baoshan dropped her, it would go very badly for both of them. But her cruel fingers digging into Lan Yi’s ass precluded that, and her power washed over Lan Yi with devastating certainty, making her shiver.

“You’re arrogant,” Baoshan said. “You’ve doomed yourself. If you’re lucky you haven’t also doomed your sect. But that doesn’t matter right now, does it? What matters is this.” She leaned in, pressing Lan Yi’s thighs further apart, and licked a long, hot line up Lan Yi’s pussy.

It felt like being struck with the discipline ruler. Her whole body jerked, sensation coalescing into horrible, grasping need at the core of her. Baoshan didn’t even pause to check on her; when Lan Yi gasped, she redoubled her efforts, sucking and licking as Lan Yi thrashed around her.

“You never learned,” Baoshan said. “I meditated on it, hoped for it. You. Never. Learned.” She shifted suddenly, one hand moving from Lan Yi’s ass to press three fingers inside her. They went in easily, Lan Yi’s body lit up with sensation and desperate for more. She had to cling to Baoshan with her legs like this, supported with only one of Baoshan’s hands. It made the whole thing feel precarious. Dangerous.

It made the Yin Iron howl with satisfaction, resentful energy curling into Lan Yi’s flesh alongside Baoshan’s fingers, settling in her bones.

“Baoshan,” she said, panting when her fingers stilled. “Please -”

“Tell me you understand,” Baoshan said. Her fingers didn’t move, held stiff inside Lan Yi. “Tell me you know what you’ve done.”

She did. Somewhere in the back of her mind, terror lurked, awareness of an irrevocable mistake. But she couldn’t think of that right now. Not when the Yin Iron had hold of them both, not when Baoshan was looking up at her with an unfathomably dark gaze, red-rimmed eyes hungry.

“Please, darling, please. Fuck me. Please.” Shame was only a vague memory. Baoshan’s lips curled in cruel satisfaction as she leaned in and flicked her tongue over Lan Yi’s clit, curling her fingers and pressing against the spot that made Lan Yi scream.

“Yes, yes,” Baoshan breathed against her. It was all over after that: she came hard and fast, so wet she could hear herself around Baoshan’s fingers, tugging Baoshan’s hair and screaming into the frigid silence of the cave.

As her breathing calmed, she felt the Yin Iron again, resentful energy creeping through her mind. Baoshan still held her, but her movements had grown less precise - impatient, Lan Yi thought, for more.

You can give her more, whispered that malignant energy.

She could. She could. Baoshan hadn’t come yet. She watched Lan Yi with bright eyes, pain overlaid with desire. It was a look that made her shiver with anticipation, with greed.

“You gave me what I wanted,” she said. “Would you let me take what you want?”

Baoshan frowned, easing Lan Yi to the ground. It was a distant expression, the way a person might look hearing fighting from another room. “What is it you think I want?”

Lan Yi answered by summoning her guqin again. This time, she freed its strings with a twist of her hand, sending them into the air to press against Baoshan’s skin, binding her legs and arms to the cave wall. It had been her spiritual instrument these forty years; it responded with quivering joy when Lan Yi asked something new of it. Now, she asked it to press into Baoshan’s skin, so that her flesh stood out against the strings in sharp relief, a single wrong movement away from cutting her.

Baoshan didn’t say anything. She barely breathed. She only watched Lan Yi with bright eyes, her power banked for the moment, a hound circling its master’s legs.

“Baoshan,” Lan Yi said. “If I let you go now, will you run away?”

“You know I can’t do that. Not when it’s you.”

It was her own savage satisfaction that rose in her throat to hear that - or it was the Yin Iron’s, a thousand furious souls screaming in harmony. Did it matter? Lan Yi couldn’t hold back a laugh either way. “Then I’ll fuck you, Baoshan. It wants me to. It needs it. Were you upset when you licked me? Did the Yin Iron feed on your regret?”

“The Yin Iron has nothing to do with this.”

It was a lie so bold it startled a smile out of her. “It’s the only reason I can do this.” She took a step forward, then another, until she could no longer feel the oppressive cold of the cave. Only Baoshan’s skin, warm and smelling of home. “You pushed me away last time.”

Baoshan took an unsteady breath. Lan Yi watched as the guqin string cut into her upper arm at the movement. She was so close to bleeding on her prettily embroidered robe. “You were seventeen last time,” Baoshan said, voice trembling.

At the memory? At how badly she wanted it now? Make her tell you, the Yin Iron whispered. “Did you want me, Baoshan? I was so young, but so pretty, wasn’t I? Fresh like early morning dew.” She reached out, trailing a finger down Baoshan’s cheek, watching in distant delight as Baoshan flinched away - and then leaned closer, color high in her cheeks. Desperate. “I touched myself every morning thinking of you, and every night thinking of the two of us together. I fucked myself on the same cushions you sat on when you visited me. Did you know?”

“Lan Yi.” Barely audible. Lan Yi decided she liked Baoshan like this: weak. Needy. “If you’re going to do something, just do it.”

“Why? You already brought me satisfaction.” Lan Yi reached out with her sword and pulled Baoshan’s robes aside. Her undergarment prevented Lan Yi from seeing her breasts, so she ripped it off, smiling when Baoshan gasped against her. “There. You’re so pink, Baoshan.”

“Lan Yi -”

Lan Yi leaned in and sucked a nipple into her mouth.

It only tasted like skin, but Baoshan’s response sent an earthquake through her. She thrashed and moaned, shamelessly loud, whispering and then near-screaming Lan Yi’s name. “A-Yi, sweetheart, please -”

“Shhh,” Lan Yi said, flattening her hand against the spot where Baoshan’s shoulder met her neck. “If you keep screaming it’ll tell me to silence you, you know. There are so many terrible ways to make someone be quiet. I don’t think you want those.”

Baoshan’s eyes widened and her hips - flexed, moving against Lan Yi, seeking friction. Oh my. “Unless you do want it? Do you, Baoshan? You can tell me.”

“The Yin Iron -”

Lan Yi pinched her nipples. It was too hard, too rough: Baoshan bit back a scream, and Lan Yi smiled into her skin. “I asked what you want.”

“I want us both to walk out of this cave.”

But the binding was weakening every moment. If they waited long enough, whatever walked out of the cave wouldn’t even really be a person anymore, much less two people. “I want to kiss you,” Lan Yi said, and did so.

It had never occurred to her that this might be so singularly wonderful, feeling Baoshan struggle against her as they kissed. Her nipples were so hard, so prominent, that Lan Yi’s focus kept swinging to them, narrowing like the moment before she leased an arrow from her bow. Baoshan’s breath came in gulps and throaty moans; her blunt fingernails scraped uselessly against the cave wall. Hurt her, give me her blood, give me her screams, whispered the Yin Iron, even as Lan Yi knew she’d die before she killed Baoshan.

But screaming. Screaming, she could do.

“What do you like?” Lan Yi whispered against Baoshan’s neck. She’d been biting her there for awhile; Baoshan was covered in bruises and looked all the more beautiful for it. “Should I fuck you? Or lick you? Or maybe you’d like to show me?”

“Lan Yi.”

Lan Yi licked Baoshan’s neck, tasting salt. “Hmm,” she said, and finished tearing Baoshan’s underclothes off.

Wasteful. Cruel. Baoshan would have to return home in nothing but her outer robes. It thrilled Lan Yi to think, and in turn the embarrassment, the pain, fed the Yin Iron. What a perfect arrangement this was. “Baoshan. Spread your legs.”

“I can’t move them.”

She couldn’t! The guqin strings held tight. Lan Yi laughed again. “I’m so glad,” she said, dropping to her knees.

Baoshan smelled different down here, musky and heavy. If panic had a smell, it might be this. But she was wet when Lan Yi parted her with her fingers; she was so, so open when Lan Yi licked her. “Beautiful,” she whispered into the soft skin of Baoshan’s thigh. “I wonder…” She took her knife from her belt.

“Lan Yi,” Baoshan said sharply. But whatever her objection, she only moaned when Lan Yi placed the pommel of her knife against Baoshan’s opening.

“It’s not as long as you might like,” Lan Yi said in almost-apology. She rubbed the pommel over Baoshan, watching the way her wetness gleamed against the metal, the way her muscles clenched as if to draw it inside. When she pressed it against Baoshan’s clit, Baoshan moaned, loud and shameless. “Do you like how it feels?”

“It’s cold,” Baoshan said through gritted teeth.

“Ah, I’m sorry,” Lan Yi said, and sent a spark of spiritual energy through the metal, warming it and pressing it inside all in one easy motion.

“Ahhh -! Lan Yi!”

This, this was what she wanted. Baoshan screaming, thrashing against her, a line of blood slowly trickling down her wrist where she hadn’t kept her arms still enough. This made the Yin Iron purr with satisfaction: Baoshan sobbing, begging for more as Lan Yi meanly pinched her clit, fucked her open with the pommel of her knife but didn’t quite give her enough to let her come.

She had never really done this before, but it didn’t matter. Not here, now, when every minute change in Baoshan’s reactions echoed through them both, magnified and distorted in equal measures by the Yin Iron. She remembered being afraid of her reactions to Baoshan, shy around her even when she’d grown up enough for Baoshan to see her as an equal. She remembered dozens of careful mediations of the distance between them: stepping away during a night hunt, rolling to the other side of the bed, ending a hug before it could turn into something else.

All of that was gone, replaced with preciously simple need.

“Tell me how you do it when you fuck yourself,” Lan Yi said.

“I…what?” Baoshan’s eyes were all pupil, staring down at her in beautiful incomprehension.

“Hard and fast? Slow, deep? Tell me what you like, Baoshan.”

“You,” Baoshan said, and bore down on the pommel, her wetness brushing over and down onto Lan Yi’s hand where she held the hilt.

It felt so good. But it wasn’t enough. The thing at the base of her neck, the whisper of evil growing stronger by the minute, prodded her into movement. “Good,” she said, and stood up. “Baoshan! Do you like my ribbon?”

Baoshan was truly her heart’s closest confidant. She understood instantly, eyes widening. “Lan Yi. Don’t do something you’ll regret.”

Too late. She smiled through the sudden wave of resentful energy, lifting her arms to untie her ribbon. “My dear friend, of all the things to regret, this can’t be one of them.” She watched as Baoshan’s eyes tracked her hands, the swaying of the ribbon. She had to be clenched around the pommel to keep it inside her, fighting gravity and her own overwhelming wetness. It sent a shiver down Lan Yi’s spine. “Here. For you.” She leaned forward, wrapping the ribbon around Baoshan’s neck - once, twice, the length of it laying so prettily against Baoshan’s skin, her rabbit-fast pulse. She positioned the metal centerpiece at the base of Baoshan’s throat, then looped both ends of the ribbon in her hand. “How does it feel?”

“Perverse,” Baoshan said.

Lan Yi could feel the ribbon moving in her hand, just a little, every time Baoshan inhaled. Good. “You look beautiful.” She couldn’t resist: she leaned in and kissed Baoshan, drinking her shocked moan from her lips. “I wish we had more time. I’d truss you up like a duck, and I think you’d enjoy it.”

“Lan Yi.” A gasp that was equal parts objection and desperation. “Lan Yi, please.”

“Mmm.” Lan Yi tightened the ribbon until Baoshan’s skin was red, her breaths not quite coming as deeply as they should. Then she reached down and slammed the knife hilt all the way inside.

Baoshan moaned, then gasped again as she felt the ribbon cutting into her skin. Lan Yi couldn’t hold back a smile at that. She reached down and kissed Baoshan’s jaw, her neck, her shoulder. The guqin string had cut into the meat of her bicep, and she kissed there, too, feeling the contrast between the string and Baoshan’s skin, licking the blood welling up around abused skin. “Here, Baoshan. Here. I’ll touch you. This is just for you.” She fucked into her with the hilt of her knife again, and again, angling it up, smiling into Baoshan’s skin when she got a louder moan in return. “You’re so beautiful, so perfect for me right now. I’ll remember this forever.”

“Lan Yi, please.”

“Please?”

Baoshan swallowed, her throat moving so beautifully against Lan Yi’s ribbon. She stared up at the top of the cave as she said, “Please. Touch me. Make me come.”

It was the only thing Lan Yi wanted to do in this life. “All right, then.” She knelt one more time, leaning in to suck Baoshan’s clit into her mouth and fucking her, hard enough to jolt her body painfully, feeling the Yin Iron feed off Baoshan’s desperate pain-pleasure as Lan Yi bit her, licked her, brought her closer and closer to the edge.

She came with a sharp keen, her legs shaking against Lan Yi, her hands hitting the cave behind them with a slap. Lan Yi had to sit back on her heels to watch as Baoshan twitched through the aftershocks, her whole body moving, straining against the guqin strings. Lan Yi’s ribbon was twisted against her throat, like she’d been thrashing so hard the fabric had caught on the cave wall. She was sweating hard, hair stuck to her forehead, and her breasts were flushed, her nipples bright red from Lan Yi’s abuse and still obscenely hard.

“Baoshan,” Lan Yi whispered, and then she moved as if she were in a dream.

She pressed her head against Baoshan’s thigh. The guqin strings still held Baoshan tight, but it didn’t matter: Lan Yi had two hands, and she used them, pulling the knife hilt out of Baoshan as she pressed a hand between her legs.

It was good like this, where she could look at the knife hilt, admiring how wet Baoshan had made it. It was better when Lan Yi licked it - first out of curiosity, and then out of a horrible, desperate need when Baoshan made a shocked noise, when she looked up to see Baoshan staring at her with wide eyes. She rubbed herself and licked the knife clean, then dropped it carelessly to the floor as she fucked herself, spreading her legs for better purchase, panting against Baoshan’s thigh as she came, whispering mangled endearments over and over.

Another crack in the Yin Iron’s cage. How long did they have? Eight hours, maybe less. “Baoshan. You need to go. Let me…let me. This is my mistake.”

“Lan Yi. Let me go, let me touch you.”

But the Yin Iron had found her despair, and now it exploited it. Resentful energy filled her mind, no longer held at bay by their pleasure. She clung to her own power, trying to fight the malevolence she could feel as distinctly as she felt Baoshan’s skin under her fingers. The Yin Iron could have her, yes, but it could not have Baoshan. Not now, not ever.

The last thing she saw before she lost consciousness was her love, struggling to free herself, shouting Lan Yi’s name.

She woke shivering.

Her forehead ribbon lay flat on her forehead, as precisely placed as Lan Yi herself would have done. Her guqin sat fully strung on the iced-over rock that had served as a dais for generations of Lan disciples. She was fully clothed.

She had a bite mark on her wrist.

“Baoshan Sanren,” she called out, just once. She only heard the echo of her own voice.

Good.

Very slowly, she turned to face the Yin Iron. It hovered inches above the water, roiling with fresh grief layered over generations of pain.

“Let’s see what we can do with you.” She placed her hands on her guqin and began to play.